DataBinding in ASP.NET 2.0

DataBinding in ASP.NET 2.0

Adam Calderon – C# MVPApplication Development Practice LeadInterKnowlogy

Agenda

ADO.NET New Features Binding Model Changes

ADO.NET New Features

DbProviderFactories SqlConnection Web.config SqlCommand TransactionScope SqlDataAdaptor DataSet

ADO.NET New Features - DbProviderFactory CreateCommand CreateCommandBuilder CreateConnection CreateDataAdaptor CreateParameter

ADO.NET New Features – DbProviderFactory Sample // Data Comes from Inputs on Form

string provider = ProviderNameBox.Text; string connString = ConnectionStringBox.Text; string commandText = CommandTextBox.Text;

// Get the provider DbProviderFactory fact = DbProviderFactories.GetFactory(provider);

// Create the connection DbConnection conn = fact.CreateConnection(); conn.ConnectionString = connString;

// Create the data adapter DbDataAdapter adapter = fact.CreateDataAdapter(); adapter.SelectCommand = conn.CreateCommand(); adapter.SelectCommand.CommandText = commandText;

// Run the query DataTable table = new DataTable(); adapter.Fill(table);

// Shows the results Results.DataSource = table; Results.DataBind();

ADO.NET New Features – SqlConnection Asynchronous Operation Support Failover Partner MultipleActiveResultSets (MARS) Connection String Builders

ADO.NET New Features – Web.config ConnectionStrings element

ConfigurationManager.ConnectionStrings[“MySql”].ConnectionString

Protecting Connection Strings Use aspnet_regiis.exe to encrypt

web.config <protectedData>

<protectedDataSections> <add name=“connectionStrings”

provider=“RSAProtectedConfigurationProvider” />

</protectedDataSections></protectedData>

ADO.NET New Features – SqlCommand Async Methods

Requires Async attribute on connection string

Limited to non-query command Reader or XmlReader

Begin/End ExecuteNonQuery ExecuteReader ExecuteXmlReader

3 Patterns for Async Implementation

ADO.NET New Features – SqlCommand Async Patterns (1)

// Start a non-blocking executionIAsyncResult iar = cmd.BeginExecuteReader();

// Do work while command running ….

// Block the execution until doneSqlDataReader reader =

cmd.EndExecuteReader(iar);

// Process data hereWorkWithData(reader);

ADO.NET New Features – SqlCommand Async Patterns (2)

// Start a non-blocking executionIAsyncResult iar = cmd.BeginExecuteReader();

do {

// Do work while command running ….} while (!iar.IsComleted);

// Sync up and process dataSqlDataReader reader = cmd.EndExecuteReader(iar);

// Process data hereWorkWithData(reader);

ADO.NET New Features – SqlCommand Async Patterns (3)

// Start a non-blocking executionIAsyncResult iar = cmd.BeginExecuteReader( new

AsyncCallback(WorkWithData),cmd);

// … later in your code

Public void WorkWithData(IAsyncResult ar){

// Retrieve the context of the callSqlCommand cmd = (SqlCommand) ar.AsyncState;

// Complete the async operationSqlDataReader reader = cmd.EndExecuteReader(ar);

}

ADO.NET New Features – TransactionScope Supports Dispose Pattern Determines if local or distributed

transaction are needed Objects that support ITransaction can

participate

ADO.NET New Features – TransactionScopeusing (TransactionScope ts = new System.Transactions.TransactionScope()) { bool success = true;

using (SqlConnection conn = new SqlConnection(ConnString)) { SqlCommand cmd = new SqlCommand(UpdateCmd, conn); cmd.Connection.Open(); try { cmd.ExecuteNonQuery(); } catch (SqlException ex) { // Error handling code goes here lblMessage.Text = ex.Message; success = false; } }

// Must call to complete; otherwise abort if(success)

ts.Complete(); }

ADO.NET New Features - SqlDataAdaptor New Properties

AcceptChangesDuringUpdate FillLoadOption▪ OverwriteChanges (Current and Orginal)▪ PreserveChanges (Original Only)▪ Upsert (Current Version of row)

ReturnProviderSpecificTypes UpdateBatchSize

ADO.NET New Features - DataSet New Properties

RemotingFormat▪ Binary or Xml

SchemaSerializationMode (IncludeShema/ExcludeSchema)

New Methods CreateDataReader – Creates a reader off

a Data Table

ADO.NET New Features – DataSet CreateDataReader

DataSet data = new DataSet();SqlDataAdapter adapter = new SqlDataAdapter(

"SELECT * FROM employees;SELECT * FROM customers",

ConfigurationManager.ConnectionStrings["LocalNWind"].ConnectionString);

adapter.Fill(data);

// Access the whole data set record by recordDataTableReader reader = data.CreateDataReader();

do{

while (reader.Read())Response.Write(String.Format("{0} <br>",

reader[1]));

Response.Write("<hr>");} while (reader.NextResult());

reader.Close();

ADO.NET New Features

Binding Model Changes

New Data Source Properties Binding Expressions Data Source Controls

Binding Model Changes – New Data Source Properties DataSourceID AppendDataBoundItems

Binding Model Changes – Binding Expressions (1) DataBinder.Eval

Can be used anywhere Eval (shortcut for DataBinder.Eval)

Can be used in the context of a data bound control

<%# Eval(“lastName”)%>

Binding Model Changes – Binding Expressions (2) XPathBinder.Eval

Used with Xml data anywhere Xpath (shortcut for XPathBinder.Eval)

Can be used in the context of a data bound control <%# Xpath(“Orders/Order/Customer/LastName”)

%> XPathBinder.Select

Returns a nodeset that can be assigned to bound controls Data Source

DataSource=‘<%# XPathSelect(“orders/order/summary”)%>

Binding Model Changes – Binding Expressions (3) Bind Method

<asp:TextBox …. Text=‘<%# Bind(“notes”)%>

Two-Way Binding Dynamic Expressions

Evaluated when page compiles <%$ AppSettings:AppVersionNumber %> <%$ Resources:Resource, helloString%> <%$ ConnectionString:localNWind%>

Binding Model Changes – Data Source Controls Tabular Data Source Controls

AccessDataSource ObjectDataSource SqlDataSource

Hierarchical Data Source Controls SiteMapDataSource XmlDataSource

DataSourceView

Binding Model Changes – Data Source Controls – SqlDataSource (1)

Properties for all of the actions (Delete,Insert,Update,Select) Command Parameters CommandType

FilterExpression / FilterParameters (only works with DataSet set for the DataSourceMode)

Binding Model Changes – Data Source Controls – SqlDataSource (2)

DataSourceMode Determines how data is returned

(DataSet or DataReader) CancelSelectOnNull

Canceled data retrieval if parameter is null

Binding Model Changes – Data Source Controls – SqlDataSource (3)

Command contain own set of parameters

Declarative Parameters ControlParameter CookieParameter FormParameter ProfileParameter QueryStringParameter SessionParameter

Binding Model Changes – Data Source Controls – SqlDataSource (4)

Caching Behavior CacheDuration (seconds) CacheExpirationPolicy (absolute,sliding) CacheKeyDependency (expiring the key) SqlCacheDependency (table dependent)

Created with each distinct SelectCommand, ConnectionString and SelectParameters

Binding Model Changes

Session Summary

Async Features of ADO.NET can help in some situations

ConnectionString builders New TransactionScope simplifies

transactions Binding Expressions simplify page

development New DataSource objects simplify

binding to Sql Server and Objects

Adam Calderon More info on InterKnowlogy:

www.InterKnowlogy.com Contact Information

E-mail: adamc@InterKnowlogy.comPhone: 760-930-0075 x274Blog: http://blogs.InterKnowlogy.com/AdamCalderon

About Adam Calderon Microsoft MVP – C# Microsoft UI Server Frameworks Advisory Council Developer / Author / Speaker / Teacher